Tufting machines

ABSTRACT

In a tufting machine, the needle-stroke drive-transmission mechanism is adjustable to provide a facility for varying the length of the stroke of the needle, such mechanism comprising an oscillating drive-input member, an adjustmemt-plate mounted for limited pivotal motion about a fixed axis and connected with the said drive-input member for movement thereby, and a connectinglink means coupling together the adjustment plate and the needlestroke shaft, that end of the connecting-link means secured to the adjustment-plate being variable as to position upon the adjustment plate to provide the adjustment in needle stroke.

United States Patent [1 1 Parsons 51 July 31, 1973 TUFTING MACHINES [75] Inventor: ionald l arsons, Blackburn,

Lanchashire, England [73] Ass i gnee The singer CompanyK UK.)

Limited, London, England [22] Filed: Aug. 12, 1971 [21] Appl. No.: 171,234

[30] Foreign Application Priority Data Aug. 22, 1970 Great Britain 40,559/70 [52] US. Cl 74/42, 112179 R, 112/221 [51] Int. Cl. ..Fl6h 21/18 [58] Field Search 74/42, 117; 1121221,

[56] References Cited UNITED STATES PATENTS 2,4l3,832 1/1947 Kay etal 74/42 3,108,553 10/1963 Beasley.....

3,494,077 2/1970 Clarke 2,489,513 ll/l949 Ballamy 1l2/79 R 3,593,922 7/l97l Standal 74/42 FOREIGN PATENTS OR APPLICATIONS 1,222,792 2/ 1971 Great Britain 74/42 Primary Examiner-Charles J. Myhre Assistant Examiner-Wesley S. Ratliff, Jr. Attorney-Marshall J. Breen et al.

571 ABSTRACT In a tufting machine, the needle-stroke drivetransmission mechanism is adjustable to provide a facility for varying the length of the stroke of the needle, such mechanism comprising an oscillating drive-input member, an adjustmemt-plate mounted for limited pivotal motion about a fixed axis and connected with the said drive-input member for movement thereby, and a connecting-link means coupling together the adjustment plate and the needle-stroke shaft, that end of the connecting-link means secured to the adjustment-plate being variable as to position upon the adjustment plate to provide the adjustment in needle stroke.

5 Claims, 4 Drawing Figures PATENIED JUL3 1 I975 SHEET 1 OF 2 PATENIED I975 3, 748 9 1 4 SHEEI 2 OF 2 FIE. 4.

1 TUFTING MACHINES The invention concerns tufting machines and has more particular reference to a mechanism for adjusting the needle-stroke of -such a machine.

It is the object of the present invention to provide a simple, yet effective, drive-transmission mechanism for the needle-stroke shaft of a tufting machine which will provide a facility for the ready adjustment of the extent of oscillation of such shaft, and thus a ready adjustment of the needle-stroke.

According to the present invention, a drivetransmission mechanism as aforesaid comprises a drive-input member adapted to be oscillated in cyclical manner, an adjustment-plate mounted for pivotal motion about a fixed axis and drivingly connected with such drive-input member, an arcuate formation in such adjustment-plate, and a connecting-link means pivotally mounted on such plate at a selected position in the said arcuate formation, the said connecting-link means being pivotally coupled tothe needle-stroke shaft and the pivot axis of the coupling between the connectinglink means and the needle-stroke shaft lying at the centre of curvature of the arcuate formation, at a relative dispostion of parts appropriate to an extreme position of movement of the mechanism.

Preferably, the adjustment-plate comprises a generally L-shaped member pivotally mounted for motion about a fixed axis passing approximately through the angle thereof, the drive-input member being connected to the remote end of one limb of the adjustment-plate and the arcuate formation being provided in the vertical limb thereof.

A'n indicator scale will usually be provided adjacent the arcuate formation.

The arcuate formation will preferably comprise a slot in the body of a member, alternatively a suitably curved bar may be provided upon which a bearing for the conne'cting-link means is adjustably slidable, or a curved guide may be provided on an edge of a platelike body. In a still further arrangement, an arcuate lineof holes is provided in an adjustment-plate and with a selected one or more of which a bearing for the connecting link means is engageable.

The invention will now be described further, by way of example only, with reference to the accompanying drawings illustrating one embodiment thereof and in which:

FIG. 1 is a perspective view of an adjustable needle stroke mechanism for a tufting machine;

FIG. 2 is a side elevation of the mechanism of FIG. 1, one of the side-plates having been omitted for ease of illustration, the relative disposition of parts shown being consistent with a retracted position of the tufting needles; 1

FIG. 3 is a side elevation, partly in section of the mechanism shown in FIG. 2; and

FIG. 4 is a section on line XX of FIG. 2.

Referring now to the drawings, an adjustable needlestroke mechanism for a tufting machine comprises a yoke 11 mounted on the machine main-shaft 12 by an eccentric 13, a generally L-shaped adjustment-plate 14 to which said yoke is freely connected adjacent to the remote end of one limb thereof and which is itself pivotally mounted for motion about a fixed axis, passing substantially through the angle thereof, and a connecting-link means 16 secured, at one end, at a selected position in an arcuate adjustment-slot 17 formed in the vertical limb of the plate 14 and, at the other end, to a radially directed lug 18a formed integrally with a collar l8 clamped to the needle-stroke shaft 19.

The mechanism is supported by and between spaced side-plates 21, FIG. 2, such plates carrying bearings 22 for the eccentric l3 and bearings 23 for the needlestroke shaft 19. The side-plates also receive a pin 24 which defines the pivot axis about which the adjustment-plate 14 moves.

The connecting-link means 16 comprises two elongate plates l6a arranged in spaced parallel disposition, the plates extending one at each side of the adjustmentplate 14 and of the lug 18a of the collar, the ends of such plates being freely pivotally connected with the lug and the adjustment-plate by respective pins 26,27, needle bearings 28 being provided between the lug and pin 26 andbetween the elongate plates 16a and pin 27, and suitable means being provided for securing pin 27 at a selected position in the slot.

The length of each link-plate 16a, between the pivot axes thereof, is equal to the radius of curvature of the arcuate slot 17 in the adjustment-plate 14, the centre of curvature of such slot 17 coinciding with the axis of pivot pin 26 in a relative disposition of parts appropriate to the bottom-centre.position of the needles driven by the. mechanism. By having the adjustment-slot l7 concentric with the pin 26 at the bottom-centre position of the needles, adjustment of the mechanism in no way varies the such bottom-centre position and thus the needle-stroke can be varied without the need for a corresponding adjustment of the looper position. A variation in needle-stroke will be attained by adjusting the position of pin 27 in slot 17 and will usually be ac.- companied by an adjustment in the position of the needle-plate. The arcuate extent of the oscillation imparted to the needle-stroke shaft 19 on rotation of the main-shaft, and thus the extent of the needle-stroke, will vary according to the position of pin 27 in the slot, a maximum length of stroke of the needle beingattained with pin 27 in one extreme position in the arcuate slot and a minimum length of stroke resulting from the location of the pin at the opposite end of such slot, the bottomcentre position of the needle remaining the same irrespective of the actual needle-stroke, and the timing of the needle-stroke thus being unaffectedby the adjustment. The actual adjustment will normally be made with the needles in a bottom-centre position, and for convenience a scale 29 is provided adjacent the slot to indicate, quantitatively, the position of the pin therein.

The invention is not restricted to the exact features of the embodiment described and illustrated since alcillation of the adjustment-plate may be derived fromv other than the eccentric mechanism shown.

What we claim is:

l. A drive transmission mechanism for the needlestroke shaft of a tufting machine comprising a drive input member, means for oscillating, said drive input.

member in a cyclical. manner, an. adjustment-plate mounted for pivotal motion about a fixed axis and drivingly connected with said drive inputmember for imparting a cyclical motion to said adjustment-plate, said adjustment-plate having an arcuate formation therein, a connecting-link means having one end. thereof mounted in said arcuate formation and being adjustable and pivotable relative to said arcuate formation, said connecting-link means being pivotally coupled to the needle-stroke shaft with the pivot axis of the coupling between said connecting-link means and the needie-stroke shaft lying at the center of curvature of said arcuate formation at a relative disposition thereof at one extreme position of movement of the mechanism such that said one extreme position of movement of the mechanism remains constant for different adjusted positions of said connecting-link means in said arcuate formation.

2. A drive-transmission mechanism as claimed in claim 1 further including spaced side-plates between which the adjustment-plate and the connecting-link means are disposed, the said adjustment-plate being pivotally supported from such side-plates.

3. A drive-transmission mechanism as claimed in claim 1 wherein the pivot axis of the coupling means between the connecting-link means and the needlestroke shaft lies at the centre of curvature of the armate formation at a relative disposition of parts appropriate to a bottomcentre position of the needle-stroke shaft.

4. A drive-transmission mechanism as claimed in claim 1 wherein the driveinput member comprises a yoke driven from an eccentric mechanism.

5. A drive-transmission mechanism as claimed in claim 1 further including a linear scale adjacent the arcuate formation. 

1. A drive transmission mechanism for the needle-stroke shaft of a tufting machine comprising a drive input member, means for oscillating said drive input member in a cyclical manner, an adjustment-plate mounted for pivotal motion about a fixed axis and drivingly connected with said drive input member for imparting a cyclical motion to said adjustment-plate, said adjustment-plate having an arcuate formaTion therein, a connecting-link means having one end thereof mounted in said arcuate formation and being adjustable and pivotable relative to said arcuate formation, said connecting-link means being pivotally coupled to the needle-stroke shaft with the pivot axis of the coupling between said connecting-link means and the needle-stroke shaft lying at the center of curvature of said arcuate formation at a relative disposition thereof at one extreme position of movement of the mechanism such that said one extreme position of movement of the mechanism remains constant for different adjusted positions of said connecting-link means in said arcuate formation.
 2. A drive-transmission mechanism as claimed in claim 1 further including spaced side-plates between which the adjustment-plate and the connecting-link means are disposed, the said adjustment-plate being pivotally supported from such side-plates.
 3. A drive-transmission mechanism as claimed in claim 1 wherein the pivot axis of the coupling means between the connecting-link means and the needle-stroke shaft lies at the centre of curvature of the arcuate formation at a relative disposition of parts appropriate to a ''bottom-centre'' position of the needle-stroke shaft.
 4. A drive-transmission mechanism as claimed in claim 1 wherein the drive- input member comprises a yoke driven from an eccentric mechanism.
 5. A drive-transmission mechanism as claimed in claim 1 further including a linear scale adjacent the arcuate formation. 